Why do you hang the American flag with the blue field at the top left?

I know that’s what the Flag Code says, but it seems backwards and usually they have some kind of rationale.

Reading L-to-R, you’re supposed to see the blue field (canton or “union”) first, then the stripes. It’s just a convention people are used to. I guess that’s why they call it the Stars & Stripes, not the Stripes & Stars.

Also, you don’t hang the flag with the field at the bottom because that’s traditionally thought of as a distress signal.

It’s traditional in heraldry that any flag with a canton is always displayed with the canton in the upper-left, as that is the most prominent position. This doesn’t seem very important with our flag, but in other flags the canton often identifies the ruling family or monarchy or something like that. Witness the multitude of flags with the British flag as a canton. So the canton is considered the most important part of the flag, therefore it gets the most important position regardless of orientaion.

Of course, not everyone follows this tradition; every country has their own rules and customs when dealing with their flags.